#!/usr/bin/env python3

import sys
sys.setrecursionlimit(300000)

YES = "Yes"  # type: str
NO = "No"  # type: str

def solve(X: int):
    if X >= 30:
        ret = YES
    else:
        ret = NO
    print(ret)
    return

def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    X = int(next(tokens))  # type: int
    solve(X)

if __name__ == '__main__':
    main() import sys sys sys.setrecursionlimit(300000) sys.setrecursionlimit sys setrecursionlimit 300000 YES = "Yes" YES "Yes" NO = "No" NO "No" def solve(X: int):
    if X >= 30:
        ret = YES
    else:
        ret = NO
    print(ret)
    return solve if X >= 30:
        ret = YES
    else:
        ret = NO
     X >= 30 X 30 ret = YES ret YES ret = NO ret NO print(ret) print ret return X: int X def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    X = int(next(tokens))  # type: int
    solve(X) main def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
     iterate_tokens for line in sys.stdin:
            for word in line.split():
                yield word
     line sys.stdin sys stdin for word in line.split():
                yield word
     word line.split() line.split line split yield word word tokens = iterate_tokens() tokens iterate_tokens() iterate_tokens X = int(next(tokens)) X int(next(tokens)) int next(tokens) next tokens solve(X) solve X if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main def solve(X: int):
    if X >= 30:
        ret = YES
    else:
        ret = NO
    print(ret)
    return def solve(X: int):
    if X >= 30:
        ret = YES
    else:
        ret = NO
    print(ret)
    return solve YES = "Yes" "Yes" YES NO = "No" "No" NO def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    X = int(next(tokens))  # type: int
    solve(X) def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    X = int(next(tokens))  # type: int
    solve(X) main
#!/usr/bin/env python3

import sys
sys.setrecursionlimit(300000)

YES = "Yes"  # type: str
NO = "No"  # type: str

def solve(X: int):
    if X >= 30:
        ret = YES
    else:
        ret = NO
    print(ret)
    return

def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    X = int(next(tokens))  # type: int
    solve(X)

if __name__ == '__main__':
    main()
